It is know to utilize centrifugal pumps to compress gaseous matter. Such pumps typically comprise a rotor or impeller that rotates about an axis in manner creating centrifugal force on gaseous matter that is in contact with or contained within the rotor. The centrifugal force on the on the gaseous matter creates a pressure differential that can be used to either evacuate or compress gaseous matter.
The rotor of a centrifugal pump typically comprises a plurality of radially oriented gas passageways or spiral gas passageways, either between rotor vanes or within the rotor. On rotors having spiral gas passageways, the spirals typically swirl in a direction opposite the direction of rotor rotation as the gas passageways extend away from the axis of rotation.
High pressure ratio pumps, such as pumps able to generate pressure ratios in excess of four, typically comprise multiple rotors operating in series (multistage) or utilize piston style pumps in lieu of centrifugal rotors. The use of multiple rotors makes the cost and maintenance of multistage compressors greater than that of single-stage compressors. Piston style pumps are generally not well suited for applications requiring steady-state operation.